Science of Weather: How depleting phosphorus is affecting plants

(CBS DETROIT) - Phosphorus is a mineral that plants need to grow and complete its life cycle. But in the United States, scientists say phosphorus in our soil is going to deplete within this century. 

Dr. Seung Yon "Sue" Rhee, a professor and director of Michigan State University's Plant Resilience Institute, says phosphorus fertilizer comes from phosphorus rock, which is made from the breakdown of animal bones from millions of years ago.

"Our current agricultural systems depend a lot on fertilizers," she says. "Phosphorus is one of the three main fertilizers that crops need in today's agricultural systems.

"The excretion from animals basically gives out almost 100% of the phosphorus that they take in from the plants. But now we don't really do that. There isn't this circular sort of agriculture that's going on much. So this is why phosphorus fertilizer is going to sort of continue to go down in its availability. 

"The world's reserve is expected to be depleted in several hundred years. And if we need to keep this up to feed the growing population, it's going to be a real problem. It already is. We have seen examples of it already. So a lot of fertilizer actually comes from Russia, and because of the Russian/Ukraine war going on right now, fertilizer prices have been really skyrocketing. Many places in different parts of the world like in Africa and other parts are having a really hard time producing the amount of crops they need to produce because they're not getting access to the fertilizers."

Rhee and Dr. Hatem Rouached, an assistant professor and member of the Plant Resilience Institute, have been studying plants' dependency on phosphorus. 

"The main approach, we'll say, is to improve the plant resilience to phosphorus deficiency and help the plant to have better roots that could explore more soil surface, to absorb more phosphate, and to grow better," Rouached said. 

"There is another mechanism that controls the inhibition of root and the phosphorus deficiency independently from the iron toxicity. And this is where our discovery is. This is to pave the way to manipulate the signaling pathway that we have discovered to allow the plant to continue elongating the root and looking for more phosphorus independently from the iron accumulation."

Rhee says the discovery of the newly found protein Arabidopsis root-specific kinase 1 extends far beyond plants and the regulation of phosphorus intake. It is also found in other organisms such as humans and may help in battling diseases and disorders such as cancer, heart disease and diabetes.

"We want to use this as a key to unlock the rest of the components of this regulatory mechanism, and we think that understanding that regulatory module could help us … engineer crops that will depend less on phosphorus fertilization," she said.